[PATCH] xhci: wait CNR when doing xhci resume

[PATCH] xhci: wait CNR when doing xhci resume

[Rick Tseng]

From: Rick <rtseng@nvidia.com>

NVIDIA 3.1 xHCI card would lose power when moving power state into D3Cold.
Thus we need to wait CNR bit to clear when xhci resmue as xhci init.

Signed-off-by: Rick <rtseng@nvidia.com>
---
 drivers/usb/host/xhci-pci.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 1e0236e..857ad8a 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -12,6 +12,7 @@
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/acpi.h>
+#include <linux/iopoll.h>
 
 #include "xhci.h"
 #include "xhci-trace.h"
@@ -455,6 +456,19 @@ static void xhci_pme_quirk(struct usb_hcd *hcd)
 	readl(reg);
 }
 
+static int xhci_poll_cnr(struct usb_hcd *hcd)
+{
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+	void __iomem *reg = &xhci->op_regs->status;
+	u32 result;
+	int ret;
+
+	ret = readl_poll_timeout_atomic(reg, result,
+					(result & STS_CNR) == 0,
+					1, 100 * 1000);
+	return ret;
+}
+
 static int xhci_pci_suspend(struct usb_hcd *hcd, bool do_wakeup)
 {
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
@@ -508,6 +522,12 @@ static int xhci_pci_resume(struct usb_hcd *hcd, bool hibernated)
 	if (pdev->vendor == PCI_VENDOR_ID_INTEL)
 		usb_enable_intel_xhci_ports(pdev);
 
+	if (pdev->vendor == PCI_VENDOR_ID_NVIDIA) {
+		retval = xhci_poll_cnr(hcd);
+		if (retval != 0)
+			return retval;
+	}
+
 	if (xhci->quirks & XHCI_SSIC_PORT_UNUSED)
 		xhci_ssic_port_unused_quirk(hcd, false);
 
-- 
2.1.4


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Re: [PATCH] xhci: wait CNR when doing xhci resume

[Felipe Balbi]

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Hi,

Rick Tseng <rtseng@nvidia.com> writes:
> +static int xhci_poll_cnr(struct usb_hcd *hcd)
> +{
> +	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> +	void __iomem *reg = &xhci->op_regs->status;
> +	u32 result;
> +	int ret;
> +
> +	ret = readl_poll_timeout_atomic(reg, result,
> +					(result & STS_CNR) == 0,
> +					1, 100 * 1000);
> +	return ret;
> +}
> +

instead of defining your own function...

>  static int xhci_pci_suspend(struct usb_hcd *hcd, bool do_wakeup)
>  {
>  	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
> @@ -508,6 +522,12 @@ static int xhci_pci_resume(struct usb_hcd *hcd, bool hibernated)
>  	if (pdev->vendor == PCI_VENDOR_ID_INTEL)
>  		usb_enable_intel_xhci_ports(pdev);
>  
> +	if (pdev->vendor == PCI_VENDOR_ID_NVIDIA) {
> +		retval = xhci_poll_cnr(hcd);

you could just use xhci_handshake() here, right?

-- 
balbi

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Re: [PATCH] xhci: wait CNR when doing xhci resume

[Oliver Neukum]

Am Montag, den 12.08.2019, 15:24 +0800 schrieb Rick Tseng:
> From: Rick <rtseng@nvidia.com>
> 
> NVIDIA 3.1 xHCI card would lose power when moving power state into D3Cold.
> Thus we need to wait CNR bit to clear when xhci resmue as xhci init.

Should any controller have CNR set? Why is this specific to a vendor?

	Regards
		Oliver

Re: [PATCH] xhci: wait CNR when doing xhci resume

[Greg KH]

On Mon, Aug 12, 2019 at 03:24:52PM +0800, Rick Tseng wrote:
> From: Rick <rtseng@nvidia.com>
> 
> NVIDIA 3.1 xHCI card would lose power when moving power state into D3Cold.
> Thus we need to wait CNR bit to clear when xhci resmue as xhci init.
> 
> Signed-off-by: Rick <rtseng@nvidia.com>

We need a "full" name on the from and signed-off-by lines, please.

> ---
>  drivers/usb/host/xhci-pci.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
> index 1e0236e..857ad8a 100644
> --- a/drivers/usb/host/xhci-pci.c
> +++ b/drivers/usb/host/xhci-pci.c
> @@ -12,6 +12,7 @@
>  #include <linux/slab.h>
>  #include <linux/module.h>
>  #include <linux/acpi.h>
> +#include <linux/iopoll.h>
>  
>  #include "xhci.h"
>  #include "xhci-trace.h"
> @@ -455,6 +456,19 @@ static void xhci_pme_quirk(struct usb_hcd *hcd)
>  	readl(reg);
>  }
>  
> +static int xhci_poll_cnr(struct usb_hcd *hcd)
> +{
> +	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> +	void __iomem *reg = &xhci->op_regs->status;
> +	u32 result;
> +	int ret;
> +
> +	ret = readl_poll_timeout_atomic(reg, result,
> +					(result & STS_CNR) == 0,
> +					1, 100 * 1000);
> +	return ret;
> +}
> +
>  static int xhci_pci_suspend(struct usb_hcd *hcd, bool do_wakeup)
>  {
>  	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
> @@ -508,6 +522,12 @@ static int xhci_pci_resume(struct usb_hcd *hcd, bool hibernated)
>  	if (pdev->vendor == PCI_VENDOR_ID_INTEL)
>  		usb_enable_intel_xhci_ports(pdev);
>  
> +	if (pdev->vendor == PCI_VENDOR_ID_NVIDIA) {

So all devices of this vendor need that?  Are you _sure_?  Why not just
blacklist a single device?

thanks,

greg k-h

Re: [PATCH] xhci: wait CNR when doing xhci resume

[Mathias Nyman]

On 12.8.2019 11.19, Oliver Neukum wrote:
> Am Montag, den 12.08.2019, 15:24 +0800 schrieb Rick Tseng:
>> From: Rick <rtseng@nvidia.com>
>>
>> NVIDIA 3.1 xHCI card would lose power when moving power state into D3Cold.
>> Thus we need to wait CNR bit to clear when xhci resmue as xhci init.
> 
> Should any controller have CNR set? Why is this specific to a vendor?
> 

Good point, always checking CNR in resume sounds like a good idea.

And use xhci_handshake() as Felipe pointed out, just like in xhci_reset():

ret = xhci_handshake(&xhci->op_regs->status, STS_CNR, 0, 10 * 1000 * 1000);

Rick, would you like to write a patch for this?

-Mathias

RE: [PATCH] xhci: wait CNR when doing xhci resume

[Rick Tseng]

Hi Mathias,

Thanks for suggestion.
The reason I do not use xhci_handshake() is we get build fail when configuring below as module:
USB_XHCI_HCD = m
USB_XHCI_PCI = m

Fail message as below:
ERROR: "xhci_handshake" [drivers/usb/host/xhci-pci.ko] undefined!

So I write my own function to check CNR.

Thanks,
Rick

--
nvpublic

  
寄件者: Mathias Nyman <mathias.nyman@linux.intel.com>
 寄件日期: 2019年8月13日 上午 03:39
 收件者: Oliver Neukum <oneukum@suse.com>; Rick Tseng <rtseng@nvidia.com>; mathias.nyman@intel.com <mathias.nyman@intel.com>; gregkh@linuxfoundation.org <gregkh@linuxfoundation.org>
 副本: linux-usb@vger.kernel.org <linux-usb@vger.kernel.org>
 主旨: Re: [PATCH] xhci: wait CNR when doing xhci resume 
   
 
On 12.8.2019 11.19, Oliver Neukum wrote:
 > Am Montag, den 12.08.2019, 15:24 +0800 schrieb Rick Tseng:
 >> From: Rick <rtseng@nvidia.com>
 >>
 >> NVIDIA 3.1 xHCI card would lose power when moving power state into D3Cold.
 >> Thus we need to wait CNR bit to clear when xhci resmue as xhci init.
 > 
 > Should any controller have CNR set? Why is this specific to a vendor?
 > 
 
 Good point, always checking CNR in resume sounds like a good idea.
 
 And use xhci_handshake() as Felipe pointed out, just like in xhci_reset():
 
 ret = xhci_handshake(&xhci->op_regs->status, STS_CNR, 0, 10 * 1000 * 1000);
 
 Rick, would you like to write a patch for this?
 
 -Mathias
 
 
     

RE: [PATCH] xhci: wait CNR when doing xhci resume

[Felipe Balbi]

(no top-posting, please)

Hi,

Rick Tseng <rtseng@nvidia.com> writes:

> Hi Mathias,
>
> Thanks for suggestion.
> The reason I do not use xhci_handshake() is we get build fail when configuring below as module:
> USB_XHCI_HCD = m
> USB_XHCI_PCI = m
>
> Fail message as below:
> ERROR: "xhci_handshake" [drivers/usb/host/xhci-pci.ko] undefined!
>
> So I write my own function to check CNR.

yeah, move that code to xhci_suspend(). It's valid for any XHCI host.

-- 
balbi

Re: [PATCH] xhci: wait CNR when doing xhci resume

[Mathias Nyman]

> Hi,
> 
> Rick Tseng <rtseng@nvidia.com> writes:
> 
>> Hi Mathias,
>>
>> Thanks for suggestion.
>> The reason I do not use xhci_handshake() is we get build fail when configuring below as module:
>> USB_XHCI_HCD = m
>> USB_XHCI_PCI = m
>>
>> Fail message as below:
>> ERROR: "xhci_handshake" [drivers/usb/host/xhci-pci.ko] undefined!
>>
>> So I write my own function to check CNR.

Adding EXPORT_SYMBOL_GPL(xhci_handshake) after the xhci_handshake() function in xhci.c
should solve that.

But I agree with Felipe that checking for Controller Not Ready (CNR)
is useful for any xHCI host, not just PCI xHCI hosts,
so move the CNR check to xhci_resume()

> 
> yeah, move that code to xhci_suspend(). It's valid for any XHCI host.
> 

xhci_resume()

-Mathias